Validity of the Risk of Malignancy Index 4 to Preoperative Evaluation of Patients with Adnexal Masses

Abstract

Objective:      To study the validity of the risk of malignancy index 4 in preoperative prediction for women with adnexal masses.

Materials and Methods:        A cross-sectional diagnostic study of women with adnexal masses admitted at Khon Kaen Hospital between 18^th May to 31^st July, 2015 for elective surgery. The sensitivity, specificity, positive predictive value and negative predictive value were calculated. Receiver operating characteristic (ROC) curve was used to evaluate the optimal cut-off point for the risk of malignancy index (RMI).

Results:          One hundred and sixteen women with adnexal masses were recruited (89 cases were benign and 27 cases were malignancy). The optimal cut-off point for RMI 4 in our study was 204 giving the sensitivity 82.8%, specificity 79.3%, positive predictive value 52.3%, and negative predictive value 93.2%. Using a cut-off at 450, sensitivity was 63%, specificity was 86.5%, PPV was 58.6% and NPV was 88.5%. The area under the ROC curve for the RMI 4 was 0.852.

Conclusion:    The RMI 4 had a validity to discriminate between benign and malignant ovarian tumors.